(Supported in part by NIEHS Superfund # ES04913 to D. Carpenter). As an investigation into it's use for PCB decontamination, we are collecting information on the crystal appearance and distribution of titanium dioxide (TiO2). We will compare different types of treated titanium dioxide. By the use of imaging, electron diffraction, and x-ray microanalysis we hope to be able to observe the absorption of PCB on the titanium dioxide surface. The HVEM is needed because some of the TiO2 particles are micron-sized. Preliminary results show good images of TiO2 (Anatase) and individual crystals in aggregated TiO2 particles.